CVE catalog
CVE-2021-34749
UBUNTU-CVE-2021-34749
- Severity
- Unknown
- Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 1.68% · Oct 25, 2026
A vulnerability in Server Name Identification (SNI) request filtering of Cisco Web Security Appliance (WSA), Cisco Firepower Threat Defense (FTD), and the Snort detection engine could allow an unauthenticated, remote attacker to bypass filtering technology on an affected device and exfiltrate data from a compromised host. This vulnerability is due to inadequate filtering of the SSL handshake. An attacker could exploit this vulnerability by using data from the SSL client hello packet to communicate with an external server. A successful exploit could allow the attacker to execute a command-and-control attack on a compromised host and perform additional data exfiltration attacks.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Ubuntu | snort | 14.04 | 2.9.2.2-3 | vulnerable |
| Ubuntu | snort | 14.04 | 2.9.5.3-3 | vulnerable |
| Ubuntu | snort | 14.04 | 2.9.6.0-0ubuntu1 | vulnerable |
| Ubuntu | snort | 16.04 | 2.9.7.0-5 | vulnerable |
| Ubuntu | snort | 18.04 | 2.9.7.0-5 | vulnerable |
| Ubuntu | snort | 18.04 | 2.9.7.0-5build1 | vulnerable |
| Ubuntu | snort | 20.04 | 2.9.7.0-5build1 | vulnerable |
| Ubuntu | snort | 22.04 | 2.9.15.1-5 | vulnerable |
| Ubuntu | snort | 22.04 | 2.9.15.1-6 | vulnerable |
| Ubuntu | snort | 22.04 | 2.9.15.1-6build1 | vulnerable |
Fixed-version evidence
OpenFactory catalog packages
No matching packages in this catalog.
Observed: